Identification of Metallothionein in Cultured Cells by Immunoblotting and Immunofluorescence Using a New Monoclonal Antibody

A hybridoma clone (MT45-5-3) producing an IgG-class monoclonal antibody specific for metallothioneins (MTs) was established. The monoclonal antibody (MT45) cross-reacted with mouse, rat and rabbit Cd²⁺-induced MTs 1 and 2 and Zn²⁺-induced MT 2 as assessed by enzyme-linked immunosorbent assay. When the antibody was used to detect the MTs transferred to nylon membranes after SDS-polyacrylamide gel electrophoresis, the antibody reacted with cultured human cell MTs as well as rat, mouse and rabbit MTs 1 and 2 even after carboxymethylation. The antibody could be used for the indirect immunofluorescence test for Cd²⁺-induced MTs in cultured human and mouse cells.